Elastic-fluid turbine



May 22, 1923.

J. WILKINSON ELASTIC FLUID TURBINE Filed Dec. 29, 1921 l'nve'r'flzo'r-James Wilkinson,

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ELASTIC-FLUID TURBINE.

Application filed December 29, 1921. Serial No. 525,686.

To all whom it may concern-.-

Be it known that I, JA ES WI INSON, a citizen of the United States,residing at Schenectady, in the county of Schenectady, State of NewYork, have invented certain new and useful Improvements in Elastic-FluidTurbines, of which the following is a specification.

The present invention relates to elastic fluid turbines and has for itsobject to provide an improved bucket or blade structure.

For a consideration of what I believe to be novel and my invention,attention is directed to the accompanying description and the claimsappended thereto,

In the drawing Fig. l is a side elevation of a part of a turbine rotorelement having blades or buckets embodying my invention; Fig. 2 is aradial sectional view of Fig. 1 taken between two adjacent blades, andFig. 3 comprises three sectional views marked X, Y and Z of adjacentblades, the views being taken on lines X-X, Y-Y and ZZ, respectively,Fig. 1.

Referring to the drawing, 5 indicates a turbine rotor member here shownin the form of a disk or wheel. Mounted on its periphery is a ring ofblades or buckets 6 which may be attached to it in any suitable manner.The foregoing is to be taken as typical of any turbine rotor comprisinga carrying member with a ring or rings of blades or buckets mountedthereon.

According to my invention, I provide blades or buckets of such shapethat when mounted on the carrying member the ratio of the pitch to thewidth of blade or bucket is constant, or substantially constant,

throu hout the length of blade or bucket.

By pitch is meant the distance between blades, being the distanceindicated by a in Fig. 3, and by width of blade is meant the distancebetween the entrance edge and the exit edge indicated by Z) in Fig. 3.At every point throughout the length of the blades %=constant. To thisend the blades are This gives a constant ratio between pitch and width,sincethe blades all radiate from the center of the rotor. Furthermore, Ipreferably shape the blades so as to obtain uniform overlap, by overlapbeing meant the amount which the concave side of a blade overlaps theconvex side of the next adjacent blade. With blades having a uniformtaper converging to the center of the rotor, uniform overlap is obtainedby a blade, having a radius of curvature which increases uniformlythroughout its length from root to tip.

It is well recognized that for given conditions, a certain ratio ofpitch to width and a certain amount of overlap gives the highestefficiency. With blades of uniform width, however, these conditions mustbe successively compromised. It is clear that with such blades if theratio of pitch to width has its most eflicient value midway between theends of the blades then toward the roots the ratio becomes too smallwhile toward the tips it becomes too great. In other words, the bladesare too close together at their roots and too far apart at their tips.Also if the overlap is correct midway between the ends of the blades,then it becomes too great at the base and insufficient at the tip. By myinvention I overcome these difficulties and thereby increase theefficiency of the blade ring.

In accordance with the provisions of the patent statutes, I havedescribed the principle of operation of my invention, together with theapparatus which I now consider to represent the best embodiment thereof,but I desire to have it understood that the apparatus shown is onlyillustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is

1. In an elastic fluid turbine, a carrying member and blades projectingradially there-- from, the ratio of pitch to width being substantiallyuniform throughout the length of the blades.

2. In an elastic fluid turbine, a carrying member and blades projectingradially therefrom, said blades being widest at their tips and taperingtoward the roots,

3. In an elastic fluid turbine, a carrying member andblades projectingradially therefrom, said blades having substantially uniform overlapthroughout their length.

4. In an elastic'fluid turbine, acarrying member and blades projectingradially therefrom, the ratio of pitch to width being substantiallyuniform throughout the length of the blades, and said blades havingsubstantially uniform overlap throughout their lengths.

5. In an elastic fluid turbine, a carrying member and blades projectingradially there "from, saidblades being widest at'their tips and taperingtoward the roots, the taper being along lines which converge to thecenter of the carrying member.

6. As an article of manufacture, a turbine blade which tapers outwardlyfrom its root to its tip." e i 7. As an article ofmanufacture, a turbineblade which tapers outwardly from its root gradually increasing carryingmember;

In witness whereof, I have hereunto set my hand this 28th day ofDecember, 1921.

JAMES WILKINSON;

